Right, but you can still program the difference...and allow an override in those locations.
Alternately (and probably more effective), you just offer duplicate buttons in those establishements that SAY "kids blah blah", when they're actually duplicates of the adult items on the POS system. No difference (price or offering) other than which button the CM pushes. In terms of inventory control...you just bucket them to the same places.
I've done similar stuff (though I'm not in retail, so it's not in POS) before (I'm an IT guy, FYI).
And it solves any problems arising from human enforcement/errors.
The reasoning behind it would be that it's not worth the resource/training investment, I guess...but, from my experience, it's a relatively easy change on the programming and DB side of things (so it doesn't seem like it would be much in the way of resources, there). Sure, there's opportunity for error on the CM side...but the opportunity is probably greater, now.